Abstract: The invention is a container for liquid product in marine transport situations, the container comprising a resilient or elastomeric membrane positioned within the confines of the marine transport vessel. The containment membrane is composed of a suitable material impermeable and inert to the liquid product, of sufficient strength and thickness to contain the liquid without spillage under stress situations. The membrane is supported within the confines of the marine vessel structure by a system consisting of a liquid jacket, preferably seawater, filled to a hydrostatic level closely approximating that of the contained liquid product and, by a plurality of restraining tie members.